Knotting head



F. E. KALNING KNOTTING HEAD Aug. 29, 1967 Filed Jan. 18, 1965 Patented Aug. 29, 1967 3,338,273 KNOTTING HEAD Frederick E. Kalning, Quincy, Mass., assignor to United Mattress Machinery Company, Quincy, Mass., a corporation of Maine Filed Jan. 18, 1965, Ser. No. 426,135 4 Claims. (Cl. 140-101) ABSTRACT OF THE DISCLOSURE The disclosure of the invention comprises a rotary knotting head for use in a wire tying machine consisting of a cylindrical body having external rotary bearing surfaces, an axially disposed wire receiving bore, a radial entering slot to said bore and an end face having formed thereon a segmental extension providing along one edge thereof a transverse wire wrap surface extending across said face spaced from said bore at one side of said slot, in which there is provided an inwardly projecting plug of a hard wear-resistant material mounted within said body displacing a portion of said wire wrap surface adjacent said bore, and having a wire contact bending surface of an area adjacent said end face and extending from a loca tion substantially opposite the rotational axis of the knotting head in the wire wrap lead direction. The plug is adjustable in a plug receiving aperture to locate said wire contact bending surface a predetermined distance from the knotting head axis in accordance with the gage of the wire by means of a backing screw threaded into said aperture. The plug is formed with a wire end engaging surface and an abutment which engages with a partially blocked end or shoulder of the aperture.

The present invention relates to an improved knotting head for use in a wire tying machine, and is herein disclosed as embodied in a Wire machine adapted for tying in the ends of coiled bed springs.

The rotatable knotting head which forms more specifically the subject matter of the invention comprises generally a cylindrical element externally supported for rotary movement and formed with gear teeth by which it is driven. An axial bore extending the length of the knotting head and connected by a radial slot with the periphery thereof is adapted to receive a segment of the preceding convolution of the wire about which the end is to be tied. One end face of the knotting head is formed with a segmental extension having an edge shaped to provide a planar wire wrap surface which extends across said face at one side of and spaced from the central bore. The wire end, held in an offset position with relation to the wire segment passing through the central bore is bent transversely against said end face to be engaged and tightly 'wound about the held wire segment by said wrap surface as the knotting head is turned on its axis.

In order to obtain a tight wrap of the wire end and a firm bond with the wire portion to which it is attached the knotting head must be manufactured to tolerances so close as to require the use of different knotter heads for different wire gages. The knotting head further is subject to. heavy wear necessitating frequent replacement in order to maintain a satisafctory level of performance of the machine. a

It is a principal object of the invention to provide an improved knotting head having provision for adjustment in accordance with the wire gage of the coiled springs being tied.

It is a further object of the invention to provide means for adjusting said knotting head to compensate for wear on critical work engaging surfaces of the knotting head and thereby to substantially prolong the working life of this expensive working tool.

With these and other objects in view as may hereinafter appear the several features of the invention will be readily apparent to one skilled in the art from the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is an exploded view in perspective of the knotting head illustrating my novel hard surface wire end bending element and the adjustable backing screw therefor in a withdrawn position;

FIG. 2 is an end view of the knotting head shown in FIG. 1 with a portion of the segmental extension for bending the wire end broken away in section to illustrate the hard surface wire bending element and adjustable backing screw therefor in operative position;

FIG. 3 is a sectional plan view taken on a line 33 of FIG. 2;

FIG. 4 is a fragmentary view partly in section illustrating the knotting head and associated portions of the machine including the knotting head bearing support, and the end plate and clamps by which the wire coil is held for the knotting of the wire end about a segment of the previous convolution of the wire; and

FIGS. 5, 6 and 7 are somewhat fragmentary views of the knotting head illustrated in FIG. 4 looking from the right illustrating successive positions of the knotting head taken while forming a first Wrap of the wire end about the wire segment supported centrally of the knotting head.

Inasmuch as knotting heads of the general configuration shown and wire machines in which such knotting heads are mounted for tying in the ends of spirally coiled bed springs are well known in the art as shown for example, in the United States Patent to Piliero, No. 3,043,347, for Spiral Compression Spring and Method and Machine for Making Same, and is readily available for reference, only so much of said said machine will be shown as believed necessary to show the connection of the present invention therewith.

Elements of the machine illustrated particularly in FIGS. 2 and 4 of the drawing include the knotting head 10 externally supported in a bearing support 12, a sup porting head 14, and holding and clamping devices such as that designated at 16 for securing a coiled spring 18 to the supporting head 14. It will be noted that the hearing support 12 has formed therein a vertically extending slot 19 which for the position of the knotting head assembly shown in FIG. 2 is in alignment with a slot formed in the supported knotting head 10 hereinafter more fully described.

For the performance of the knot-tying operation the large end convolution 20 of the coil 18 is suitably mounted by means of the clamps 16 referred to the supporting head 14 so that the wire end designated at 22 extends somewhat beyond the segment of wire or about which the wire end is to be wrapped.

The knotting head 10 is generally cylindrical in shape having fonmed thereon an external gear 23 adjacent peripheral bearing surfaces 24, an axial bore 26 extending the length of the knotting head 10, and a radial slot 28 extending radially inwardly from the periphery of the knotting head. The bore 26 is comically enlarged as at 30 to receive a bending element 32 which operates in a well-known manner to produce an oflfset in a portion of the coiled wire in advance of and adjacent the knot.

The opposite end face 34 of the knotting head is formed with a segmental extension 36 having one edge thereof shaped to provide a transverse wire wrap surface 38 which extends across said end face at one side of and spaced from the axial bore 26. The transverse wire wrap surface 38 is spaced from the axial bore 26 by an amount which will cause the surface 38 to engage with and tightly wrap the wire end 22 around the centrally held segment of the previous wire convolution to form a desired knot.

In my improved knotting head illustrated in the drawing, a small adjustable plug 40, formed of a very hard,

. wear-resistant material which may, for example, be tungsten carbide, is mounted in the knotting head body to project slightly above the transverse wire wrap surface 38 at a point slightly offset from the rotational axis of the knotting head. The expose-d end of the plug provides an area of hardened wire wrap surface at the point of hardest usage and greatest wear extending from a point opposite the rotational axis of the knotting head in the wire wrap lead direction, to bend and to press the bent wire 22 firmly against the centrally supported wire segment. I have found that a very large portion of the wear which takes place in the knotting head is absorbed by my newly added plug 40 placed in the position described and shown with the result that the useful life of this important and expensive tool is greatly extended. In the illustrated construction the plug 40 is mounted in a drill 42 which extendsinwardly through the segmental extension 36 of the knotting head 'body in the same transverse plane with the end face 34 along a line passing to one side of the rotational axis of the knotting head. The drill 42 is threaded to receive a longitudinally adjustable backing screw 44. It will be noted that the drill 42 is located in the segmental extension 36 of the knotting head 10, is perpendicular to the transverse wire wrap surface 38, and terminates at the point at which one half of the bored hole emerges through the transverse wire wrap surface 38. The inner end of the plug 40 is formed with a semicircular extension 46 which projects above the wire wrap surface 38 by an amount controlled by the adjustment of the screw 44. The flat'side of the extension 46 engages againstthe end face 34 to prevent rotational movement of the plug 40. For a position of extreme outward adjustment of the plug 40 the shoulder formed at the base of the semicircular extension 46 will engage the partially blocked end of the drill 42 thus locking the plug in.

The apparatus shown is arranged to operate in the following manner. The wire coil is mounted on the end plate 14 substantially in the manner shown by clamps 16 such as that shown in FIG. 4 with the free end of the Wire projecting beyond the point at which the knot is to be tied. The knotting gear assembly including the bearing support 12 and knotting head 10 is then moved upwardly with relation to the end plate 14 causing a segment of the previous convolution of wire to enter the aligned slots 19 and 28 formed respectively in the bearing support 12 and in the knotting head 10, and the wire end 22 to engage with a shallow notch 48 formed in the bearing support 12 within which the knotting head 10 is rotatably supported, causing the wire end 48 to bend sharply upwardly and to engage against the end face 34 of the knotting head 10 in the path of movement of the transverse wire wrap surface 38 and in position to be wrapped about the segment of the preceding convolution of wire held in the axial bore 26 as shown in FIG. 4. This position of the parts preparatory to the start of the wire wrap operation is that shown also in FIG. 5. During subsequent rotation of the knotting head 10 the wire end 22 is engaged by the transverse wire wrap surface 38 and rotating with the knotting head in a counterclockwise direction to engage with and wrap the wire around the centrally supported segment of the wire coil as illustrated by the successive views 6 and 7.

During this operation the exposed wire bending end surface of the plug 40 engages a portion of the wire end 22 immediately in advance of the wrapped portion engaging with and extending tangentially away from the wire segment about which the wire end is wrapped. The distance of the wire engaging surface of the plug 40 away from the rotational axis of the knotting head is gage-d with relation to the wire size to cause the wire end to be wrapped tightly about the supported wire segment.

Since most of the wear which takes place in the knotting head is concentrated in the area of the wire wrap surface displaced by the wire bending surface of the plug 40, any such wear which may appear is readily compensated for by adjustment of the backing screw 44. This adjustment coupled with the fact that the plug is preferably composed of a very hard wear resistant material such as tungsten carbide and is in any event readily replaceable has the effect of greatly increasing the life of the knotting head. A further advantage of my improved knotting head consists in the fact that it may be readily adjusted for use with wire of all different gages. To effect this adjustment the backing screw 44 is adjusted to position the wire bending surface of the plug 40 with relation to the gage of the wire segment and bent wire end to cause the wire to be turned tightly around the axially held segment of the previous coil.

The invention having been described what is claimed 1. In a rotary knotting head for use in a wire tying machine comprising a cylindrical body having external rotary bearing surfaces, an axially disposed wire receiving bore, a radial entering slot to said bore and an end ,face having formed thereon a segmental extension providing along one edge thereof a transverse wire wrap surface extending across said face spaced from said'bore at one side of said slot, the combination of an inwardly projecting plug of a hard, wear-resistant material mounted within said body displacing a portion of said wire wrap surface adjacent said 'bore, and having a wire contact bending surface of an area adjacent said end face and extending from a location substantially opposite the rotational axis of the knotting head in the wire wrap lead direction.

2. In a rotary knotting head [for use in a wiretying machine comprising a cylindrical body having external rotary bearing surfaces, an axially disposed wire receiving bore, a radial entering slot to said bore and an end face having formed thereon a segmental extension providing along one edge thereof a transverse wire wrap surface extending across said :face spaced from said bore at one side of said slot, the combination of a plug formed of a hard, wear-resistant material adjustable along a path within said cylindrical body to project through said transverse wire wrap surface, and providing a wire contact bending surface displacing a portion of said Wire wrap surface of an area extending from a point substantially opposite the rotational axis of the knotting head in the wire wrap lead direction, and means for adjusting said plug in said path to [locate said wire contact bending surface a predetermined distance from said knotting head axis in accordance with the gage of the wire.

3. A knotting head according to claim 2 in which said path is a plug receiving aperture extending between the periphery of said knotting head and said transverse wire wrap surface, and said adjusting means is a backing screw threaded into said aperture.

4. A rotary knotting head according to claim 1 having an inwardly extending plug supporting aperture opening into said portion of said wire wrap surface displaced by said plug and having the inner end portion of said aperture extending across the plane of said end face forming a partially blocked end of the aperture, a plug having a wire end engaging surface supporting portion extending through said opening, and having an abutment arranged for engagement with said partially blocked end of the UNITED STATES PATENTS 1,429,253 9/ 1922 Rhenst rnm 140-101 2,058,679 10/1936 Gilmore 140-101 Zimmerman 140-101 Zimmerman 140-101 Zollner 92-222 Piliero 140-101 Neely 277-235 CHARLES W. LANHAM, Primary Examiner. E. M. COMBS, Assistant Examiner. 

1. IN A ROTARY KNOTTING HEAD FOR USE IN A WIRE TYING MACHINE COMPRISING A CYLINDRICAL BODY HAVING EXTERNAL ROTARY BEARING SURFACES, AN AXIALLY DISPOSED WIRE RECEIVING BORE, A RADIAL ENTERING SLOT TO SAID BORE AND AN END FACE HAVING FORMED THEREON A SEGMENTAL EXTENSION PROVIDING ALONG ONE EDGE THEREOF A TRANSVERSE WIRE WRAP SURFACE EXTENDING ACROSS SAID FACE SPACED FROM SAID BORE AT ONE SIDE OF SAID SLOT, THE COMBINATION OF AN INWARDLY PROJECTING PLUG OF A HARD, WEAR-RESISTANT MATERIAL MOUNTED WITHIN SAID BODY DISPLACING A PORTION OF SAID WIRE WRAP SURFACE ADJACENT SAID BORE, AND HAVING A WIRE CONTACT BENDING SURFACE OF AN AREA ADJACENT SAID END FACE AND EXTENDING FROM A LOCATION SUBSTANTIALLY OPPOSITE THE ROTATIONAL AXIS OF THE KNOTTING HEAD IN THE WIRE WRAP LEAD DIRECTION. 